Method of conditioning regenerated cellulose for use in the arts



June 23, 1936- w. M. STEVENSON 2,045,493

METHOD OF CONDITIONING REGENERATED CELLULOSE FOR USE IN THE ARTS FiledFeb. 1, 1953 Patented June 23, 1936 METHOD OF CONDITIONING REGENER- ATEDOELLULOSE FOR USE IN THE ARTS William M. Stevenson, Springfield, Mass,assignor to Cliicopee Manufacturing Corporation, New Brunswick, N. 3., acorporation of Massachusetts Application February 1, 1933, Serial No.654,736

2 Claims.

Fabrics formed of strips cut from a web of regenerated cellulose findtheir chief utility in the trimming of hats and shoes and to a largeextent they are knit fabrics. Their individual strips or strands lacktensile strength and flexibility and'it has been necessary to treat themwith reagents of the softener type to relieve the stiffness to the pointwhere the fabric is usable in a limited field.

Regenerated cellulose in the web is expensive,.

the current price being sixty cents a pound, and present methods ofmaking it into fabrics add to the expense as well because of their useof reagents as of their very prodigality or wastefulness of the stock.This is particularly true of woven regenerated cellulose, as heretoforeproposed, which requires sixteen to twenty ounces of the material to thesquare yard, suchfabrics being embodied of hard twisted webs or strands.There is little or no demand for the hard twisted fabric on account ofits pronounced stiffness even when the weave is modified withconventional filling or reinforcing threads in an effort to overcomeinherent stiffness and to reduce the cost.

The principal objects of the present invention are to condition stripsof regenerated cellulose so that they will possess great tensilestrength and pliancy or flexibility'in contradistinction to theirinherent stiffness, and thus be admirably adapted for weaving and otherpurposes where a lustrous and sparkling or scintillating stock isdesirable; to provide for such conditioning without resort to solventsor softening agents and in such way that less stock is required persquare yard and to produce a fabric far superior to fabrics producedfrom hard twisted strands or strips.

. The nature of my invention consists in mechanically treating fiatstrips of regenerated cellulose so that they will be transformed from astate ofhardness and unyielding quality, in which state they aresusceptible to splitting and tearing, to a state of pliancy andflexibility and,

'45 for all practical purposes, free from splitting or tearing tendency.Referring to the accompanying drawing which illustrate, in principle andsubstance, one way of practicing the invention,-- Figure 1 is aschematic or diagrammatic view of the method and means of my invention.

2 is a detail illustrative of the lateral traverse of the die.

,Fig. 3 is a detail, on an enlarged scale, illus-' 'trative of thecrushing or involuting action of the die.

Figs. 4 and 5, respectively, are sectional views of the strip before andafter being acted upon by the die.

According to my practice, .flat strips 5, of desired width, are'cut froma web 6 of regenerated cellulose. In this state the stripsare relativelyhard and inelastic and possessed of undesirable stiffness and a loworder of tensile strength. In order to remedy these conditions I modifythe starting product by first plicating it, as it were, 10 in alengthwise direction and then squeeze or crush it upon itself to providea uniformly soft and pliable strand or ribbon possessed of relativelygreat tensile strength and which in crosssection is distinguished by itslabyrinthian struc- 15 ture. In the accomplishment of this resultvarious means may be availed of but under preferred practice the strips5, under proper tension, as by the use of rolls 1, are drawn throughdies 8 which are elements with restricted axial 20 cylindrical bores 9.

The purpose and effect of the described mechanical treatment is toreinforce the hard, inelastic strip or starting product by first turningits longitudinal margins Ill and then involuting 25 the mass withcontemporaneous squeezing, crushing or crinkling which reduces it to amore or less densified and compact state manifested by a cellular orlabyrinthian structure, Fig. 5, which accounts for its increased tensilestrength and 50 its pronounced softness and pliancy and its addedsparkle. It will be manifest to those skilled in the art that themechanical treatment of my invention is not to be confounded with thewellknown and conventional practices of spiral wind-- 35 ing or twistingof one or more threads.

Before therelatively hard and inelastic flat strips of commerce aredelivered to the dies, I prefer to dust or spray them, as at H, with alubricant such as paraffin or other wax. This 40 treatment helps to easethe stock through the die and also operates to reduce friction of theparts as they pass over from the flat phase to the labyrinthian orinvoluted phase.

The soft and pliant strands or ribbons l2 as 5 they pass from the diesare wound upon spools or bobbins l3. The latter are disposed relativelyclose to the dies to preclude any opening up of the strip such as mightpossibly occur were the strips allowed to run free or be delivered tothe 50 bobbins a remote distance from the dies. In this connection therealso is merit in providing for lateral traverse of the dies as indicatedin dotted lines in Fig. 2.

From the foregoing it will be. manifest that 55 the eifect of crushingor compacting the strips is greatly to increase their tensile strengthand substantially to obviate any tendency towards splitting or tearing,and, of equal importance, to reduce the original hard abrasive strip toa condition of marked pliancy, softness, and flexibility, whereby it isparticularly adapted for weaving. And in connection with weaving it mayhere be remarked that another merit of the invention is that itconditions the ordinary stock without such prodigality thereof asoccurs, for

example, in hard twisting or similar densifying operations. Hence, inthe weaving of fabrics a pound of regenerated cellulose will go muchfurther under my practice than under the old practices.

What is claimed as new:-

1. The method of conditioning hard surfaced regenerated cellulose toadapt it to weaving. which consists in providing relatively narrowribbons of that material, waxing a surface or surfaces of the ribbonswhile maintaining them in fiat state, destroying the surface hardness ofthe ribbons without the application of twist by lapping the ribbons uponthemselves thereby reversing their longitudinal edges, and immediatelywinding the lapped strands on individual bobbins.

2. The method set forth in claim 1, wherein the bobbins are disposedrelatively close to the instrumentalities for destroying the surfacehardness of the ribbons and such instrumental- 15

